1. Technical Field
The present invention relates in general to improved data processing systems and in particular to improved methods for interchanging data within a data processing system. Still more particularly, the present invention relates to a method and apparatus for the efficient interchange of multimedia data with variable playback speeds in a data processing system.
2. Description of the Related Art
The interchange of data within a data processing system is a well known feature of modern state-of-the-art computer systems. Text and graphics may be efficiently interchanged between data processing facilities utilizing well known modem devices or facsimile devices/cards.
Recently, modern computer systems have begun to experiment in so-called "multimedia" data. That is, presentations containing audio, video, text, graphics and image combined into a common presentation. One factor which complicates the assemblage and manipulation of multimedia data is that such data may take several forms. For example, audio data may be stored and interchanged as analog data, such as audio tape and AM or FM radio signals.
Additionally, audio data may be stored and interchanged as coded data, which includes coded values for factors such as tone, duration, loudness, etc. One example of coded audio data is the so-called Musical Instrument Digital Interface (MIDI), in which keystrokes are encoded and exchanged utilizing a common interface. Finally, audio data may be stored and interchanged as uncoded data, or data which simply represents a digital representation of an audio signal, such as the signal encoded on a compact audio disk.
The variety of forms which audio data may take has lead to great difficultly when attempting to interchange such data. This is particularly true when attempting to vary the playback speed of audio or video data. Thus, it should be apparent that a need exists for a method and apparatus which permits the efficient and accurate interchange of multimedia data with variable playback speeds in a data processing system.